Portable jib-crane



W. H. PURNELL AND J. A. BUTTERWORTH.

PORTABLE JIB CRANE APPLICATION FILED JU LY 23.1919.

1,345,8 1, Patented July 6, 1920.

Z SHEETSSHEEI I.

w. H.-PURNELL AND 1. A; BUTTERWOHTH.

PORTABLE JIB CRANE.

APPLICATION FILED JULY 23 I919 Patented July 6, 1920.

2 SHEETS-SHEET UNITED? srT PATENT orricii.

WALTER H. PUBNELL AND JUSEPH A. BU'TTEE'WOBTH, OF LOUGHBOROUGH, ENGLAND,

ASSIGNORS TO EEERBEBT MORRIS, LIMITED.

PORTABLE QUE-CRANE.

Specification of Letters Patent.

Patented July 6, 1920.

Application filed July 23, 1919. Serial No. 312,659.

To all whom it may concern:

Be it known that we, lVAnrnn HENRY PURNELL and Josnrrr ALEXANDER BUTTER- woRrH, subjects of the King of the United Kingdom of Great Britain and Ireland, and residents of Loughborough, England, have invented a certain new anduseiul Improvement in and Relating to Portable Jibhanes, of which the following is a specltication.

This invention relates to portable jib cranes of the type mounted on carriages and having fixed posts and jibs.

Such cranes, which are used chiefly in Workshops and warehouses for raising and transporting heavy parts or packages, are usually themselves quite heavy in proportion to the weights they are capable of raising, so that, when loaded, even small cranes of this type require a considerable effort to move them upon the floor or along a track. This disadvantage is overcome by the invention which presents a light and yet substantial structure capable of being moved and operated by a much less ellort than any of the usual constructions.

Broadly, the invention consists in a portable jib crane comprising a carriage constituted by three triangularly arranged wheeled units, independently formed arms connecting one of the units with the two remaining units, said arms containing between them a substantially ll-shaped open space, and a post and jib sustained by the first mentioned. unit.

In the accompanying drawings Figure 1 is a side elevation and Fig. 2 a sectional plan of a portable jib crane according to the invention.

In the construction according to the invention, the carriage, in lieu of being formed of: one casting as usual, is composed of three small units 1., 2, 3, preferably castings, mounted on wheels, the unit or casting mounted on the rear wheel or wheels 1 being connected with the units or castings 2, 8 mounted on the front wheels 5, 6 by steel flats 7, 8 rigidly attached to such units or castings, the flats 7, 8 diverging forwardly and containing between them a t -shaped space allowing the crane to be moved near the load to permit of a vertical lift. The post 9, which is supported on the rear unit or casting 1, is of tubular formation and is connected to the jib 10, which is also tubular,

by a bracket 11 having tubular extensions 12, 13 in sleeve engagement with, and attached to, the post 9 and the jib 10, respectively, such bracket 11 being suitably shaped to support in bearings a guide roller 141 for the lifting rope or chain 15. Attached to the outer end of the jib 10 is a bracket 16 having a tubular extension 17 in sleeve engagement with the outer end of the jib, such bracket 16 being shaped at its outer end to support in bearings a guide pulley 18 for the liftlng rope or chain 15. j

The structure may be stiffened by means of stays 19 extending from the rear unit or casting 1 to the bracket 11 and by a stay 20 or stays connecting the bracket 11 with the bracket 16.

It will be seen that the construction described is free from the disadvantage hereinbefore referred to as experienced with prior constructions. The steel flats present, in efllect, skeleton arms of inconsiderable weight; while the tubular post, tubular jib and brackets with tubular extensions may be as light as practicable consistent with the requirement of strength.

W hat we claim is 1. In a portable jib crane in combination a carriage constituted by three triangularly arranged wheeled units, steel flats constituting arms connecting one of said units with the two remaining units said arms containing between them an uninterrupted open space, an upright tubular post mounted on the said first mentioned unit, a bracket in sleeve engagement with said post, a guide pulley supported by said bracket, a jib carried by said bracket at an inclination to said post, a bracket having an extension in sleeve engagement with the outer end of said jib, and a guide pulley supported by said last mentioned bracket, as and for the purpose set forth.

2. in a portable jib crane in combination a carriage constituted by three triangularly arranged wheeled units, steel flats constituting arms connecting one of said units with the two remaining units said arms containing between them an uninterrupted open space, an upright tubular post mounted on the said first mentioned unit, a bracket in sleeve engagement with said post, a guide pulley supported by said bracket, a jib carried by said bracket at an inclination to said post, a bracket having an extension in sleeve engagement with the outer end of said jib names to this specification in the presence of a guide pulley supported by said last menitWo subscribing Witnesses. tioned bracket, stays connecting said first mentioned unit with said first mentioned 7 WV. H. PURN ELL. bracket, and stays connecting said first men- J. A. BUTTERWORTEL tioned bracket With said last mentioned bracket,.as and for the purpose set forth.

In testimony whereof We have signed our Witnesses:

FANNY H. MALLETT, THos. H. Coon. 

